Flex Pipe Failure

[MrDBF]

Upon opening my pool this year, I was greeted with a leak. It took a while to locate and extract the damaged pipe. Turns out it was in a piece of Flex PVC pipe.

I'm trying to determine the cause of the failure... 18 years of use before rupturing. The pipe was completely encased in gunite.

Anybody seen bulging in a pipe like this? Any ideas? Didn't want to bias discussion with too many details but will answer any questions!

 

[bdavis466]

The problem was caused because flex pipe was used... This is exactly why I never recommend it's use.

Do you have a heater? Was this in The spa? Did the plumbing ever freeze?

 

[MrDBF]

Totally agree with you regarding flex pipe use. It was used in a tight bend but my repair used 45 degree rigid bend and was quite easy to plumb.

Yes, the pipe was in the return lines of a spa. A heater was used (max of 100 degrees) a couple dozen times a year.

Not sure if the plumbing ever froze.

Do think the bulging was caused by ice? It's very irregular in space.

 

[mas985]

The pipe was completely encased in gunite.

Because of this, I suspect it might of happened before gunite. The gunite should have prevented any expansion unless there was void the gunite.

 

[bdavis466]

I suspected a void as well. The way the pipe is bent and the direction the gunite was likely shot would seem to make a void an easy occurrence... It at least makes sense in my mind.